Going from 20" to 24" unicycle

Just got a new unicycle and I was so eager to ride it out of the box. I did it and I had fun, but…all did not go well. Some lessons learned:

Old Uni:
20" torker LS
5"(125 mm) cranks
300mm seat post
“skinny” free style seat

New Uni:
24" Nimbus with 3" wide tires(…actually 25.5" surface wheel diameter)
6"(150mm) cranks
300mm seat post
“fat/comfy” nimbus seat

My riding skill level:
5 month experience, ride 3-5 miles, free mount(normal and rock back), idling 5-10minutes, can do twist turns and tight “edge” turns. I can ride “low” or “high” seated positions.

Lessons Learned:

1.) Be careful going to a different crank size when buying a new unicycle. Stick with the “same size” if you are a beginner, otherwise don’t expect to open the box and just ride.

2.) What happens when going from 125 to 150mm’s? I didn’t really pay attention to the new unicycle spec during ordering, and I thought going longer(more torque) would be cool for climbing.

3.) New crank length Totally Threw off my Timing and Balance. Felt like I was a beginner, again. I would pedal and fall over. Why? Since, balancing is a function of(pedaling tension timed at specific angles during rotation) it makes sense that the longer lever arm(150mm) even though it was just 25mm’s would totally throw off my balance. I had finely tuned my body to synchronized to a 125 mm crank arm, and now with 150 the whole thing was out of wack. Cure? do a few dozen figure 8’s and free mounts to figure it out.

4.) I found that I needed to “wait” and “slow down” my reaction to maintain balance. I think that’s the effect from going from short to long cranks. I can only assume that the opposite is true, also.

5.) Longer crank means longer feet travel, higher knee raise and more “abrasions/scratches” on my leg.

6.) Fat/comfy seat means “less pedal weight” which is normally good, but on a new unicycle with longer cranks you “need” more pedal weight to stay up. Thus, I found myself enjoying what felt “like a couch” but I had to fight to stay on sometimes. With more acclimation I should get better.

7.) Going from 20" to 24" ALSO MEANS going from 300mm seat post to 200mm seat post. I thought it would be the same, but I forgot the bigger wheel size equals the need for a shorter seat. I’m 5’9" with 32" inseam. Using a “pipe cutter” took forever, because the nimbus aluminum seat post is very thick. Had I known, I would have ordered the right size.

8.) Related to “slowing down” to deal with longer cranks, I found that I had to “throw” my weight and “twist” with more force than when I was riding my smaller uni. This is especially important when free mounting. More “force” all around when mounting any method.

9.) One advantage is that the “slower” unicycle response equates to “stay up longer” and more “stability”. It’s just a matter of synchronizing your body to take advantage of that, and not “rush” it. Also, the bigger wheel seems to roll easier and “faster” than my first unicycle.

10.) Just ordered shorter cranks. I want to match the feel between my “old 20” and my “new 24”. Also, the shorter crank will give me more speed, but main reason to match is I want to avoid “transitioning” between the two unicycles. Sure, if i just wanted to develop more skills it would be valid, but I just want to get out there and ride…for now. If someone had told me this before, it would have saved me a lot of grief. Also, $80’s for new cranks. Also, I would have avoided a 6" bloody gash on my calf. Result of slightly missed free mount.

11.) This reminds me of my last point. Take those “damn spikes/studs” out of the nimbus pedals. Use a 6mm socket wrench and take them out. It came with the unicycle. I was in a rush and never thought to remove them. Spikes will come in handy, later, but not right now. Kevlar BMX pants will also be on my wishlist.

Anyways, I thought I’d share these details for posterity. Seems nobody ever mentions stuff like this. Maybe it was just an easy transition for you. Hey it would have been a disaster if I had gone up to a 26" Hatchet(…I just found out 3 units(used) were selling for $500 on amazon, as I am typing this).

Hi, Slamdance. For some reason this thread has shown up in the section for reporting bugs and administrative queries. You might like to repost it in the unicycling forum unless the moderators can move it. I switched around between three different size unicycles while I was learning, which some people felt might be a bad idea, but I’m glad I did. You pretty soon get used to the different feel of different sizes and crank lengths. I wouldn’t rush to change the cranks just to make it feel more familiar. There’s a good reason why a muni would have longer cranks, like you surmised it gives extra power. I had to get shorter cranks on my muni because otherwise, even with a short seatpost right down, I couldn’t reach the pedals properly, but if I ever start riding it seriously I think I will get the frame tube cut down instead. I’m quite light - only about 120lbs - and it feels like I don’t have enough weight to throw at it.

I agree. Don’t try to turn your new unicycle into your old unicycle.

Onetrackmind came up with some interesting research findings that are discussed in this thread: Scientific backing for having multiple unis

Wow, you are a very sensitive unicyclist! Almost to the point where one might be inclined to ask: Are you a bot? :slight_smile:

When I think back to my early days of unicycling I remember being happy to have something to ride. But since all of my learning was on borrowed equipment, I was less interested in the minor details, I guess.

On the other hand, when I transitioned from a 24" to a 20" for doing Freestyle (in my 3rd year of riding), that was a very irritating switch! It took me months to get the “feel” for the shorter distance the uni would move with half a pedal turn, which is key to doing nearly any type of trick. I was always missing simple mounts & things because my brain hadn’t switched over to 20" mode. I can’t remember if they had different crank lengths, but that would have been a much smaller factor than wheel size.

Remember also the biggest difference between your new 24" and your old 20" is that it’s heavier. Even if it weighs about the same as your old one, the wheel mass being in a larger circle makes it more sluggish to move. And of course it goes a different distance with each push of a pedal. You already know that part.

I have to agree with the previous responders that this is a different unicycle that has different strengths and weaknesses. Changing the crank length isn’t going to make them ride the same anyway. For a 24" Muni, 150 mm cranks is a good size. 125 would only be a good size if your trails are relatively flat and easy. But if your goal is to go faster, 125 will definitely help with that. In fact, I just checked and you don’t mention Muni at all, so if you’re riding on pavement, I definitely recommend 125 or shorter. That’s the size we use for Track racing, and is also a great all-around size for non-Muni applications.

you’ll swiftly get used to the difference. If you want to quicken the time it takes to get comfortable with both, try to ride other unicycles if you have any available in your area. There’s nothing like transitioning from a 12" wheel with 3" cranks to a 45" wheel with 150mm cranks! Or from that Big Wheel back to a 20". You will ride herky-jerky for a moment, but if you’ve ridden that one a lot before, you will smooth out quickly.

To help your learning, and if I’ve understood what you’re saying, this is not the reason you needed a ‘shorter’ seat - it’s because you have longer cranks, so the bottom of the pedal stroke is further away from the seat, relative to your other cranks. The wheel size makes no difference.

Of course, other factors might dictate how low you position your saddle, but to get like-for-like leg extension at the lowest point, your saddle is going to be lower the longer the crank.

Well about 2 months after I learned to ride I went from a 20" uni with 125s to a 26" with 150s. 125s would have been horrible on the 26" at that stage of my learning, as not enough torque to control the bigger wheel. Sure the 26" felt very different, but the longer cranks were the least of my worries (in fact I returned the cranks to be changed as they’d sent the wrong length, so made my first rides on it with 175 cranks I took off a bike!) As others have said, don’t try to make it feel the same as your other uni because it won’t. Also it’s worth reading the link Spinningwoman gives - it explains why a lot of us find that riding multiple different unis helps with the learning process. Personally I spent a few sessions deliberately riding my two unis back to back in order to teach my brain how to cope with things being different and still often ride multiple different unis in a session.